Risk of biochemical recurrence in patients with a positive surgical margin after radical prostatectomy

Serum prostate specific antigen (PSA) is an irreplaceable marker in the detection and follow-up of patients with prostate cancer. In our analysis we addressed factors that could indicate the likelihood of biochemical recurrence (BCR) early after radical prostatectomy. We mainly focused on the positive surgical margin (R1).

Retrospective evaluation and analysis of the database of patients with prostate cancer after radical prostatectomy from 2001 to 2019. In total 1529 patients were enrolled in the study. The median follow-up was 48 months. The age of the patients ranged from 49 to 76 years. We used pre-operative PSA values, and the monitoring of the dynamics of 3rd generation PSA progression (detection limit 0.003 ng/ml) at month 1 and month 3 after surgery and then in 3-month intervals. We monitored the surgical margin positivity (R0 negative, R1 positive) and the Gleason score (GS) based on histological samples and we analysed the relationship to biochemical recurrence of the disease.

The pre-operative PSA value did not show a direct relationship to the R1 risk. Patient values in the groups R1 and R0 differed only by 1.159 ng/ml (p=NS). The 3rd generation PSA value at month 1 after surgery was 50.82% higher in R1 patients (p>0.001). 50% of patients with R1 (29.5% patients of the total) did develop BCR during the follow-up period, while in patients with R0 (70.5% patients of the total) this proportion was 30% (p>0.001). Among those with GS 67, 47% developed BCR. The GS 810 group relapsed in 75% of the cases (p>0.001).

According to our analysis 33% of the patients reached the stage of biochemical recurrence. We demonstrated a direct dependency between the risk of recurrence and the final Gleason score. The presence of R1 should not be viewed as a direct indication for adjuvant radiotherapy.